Answer:
We can relate the kinetic energy of the particle to the potential difference between the plates by following equations:
Work energy theorem:




So,

If the distance is doubled and the potential difference is halved, then

Explanation:
As can be seen from the relationship between kinetic energy and the potential difference, the distance between the plates has no effect on the relation between kinetic energy and the potential difference. Since the charge of the second particle is equal to that of the first one, the new kinetic energy would be half of the first kinetic energy.
The average velocity of Sandy is given by the total distance covered S divided by the total time taken t:

The total distance covered is

while the total time taken is 2 hours + half an hour (for the rest) + 1 hour and half, so

Therefore, the average velocity is
Answer:
The electric field is 
Explanation:
From the question we are told that
The radius of the metal sphere is 
The excess charge which the metal sphere carries is 
The distance of the position being to the center is 
The coulomb constant is 
Generally the electric field is mathematically represented as

substituting values


The answer to this question is:
C-"That moving clocks run slower"
Your Welcome :)
Answer:
Explanation:
We define the linear density of charge as:

Where L is the rod's length, in this case the semicircle's length L = πr
The potential created at the center by an differential element of charge is:

where k is the coulomb's constant
r is the distance from dq to center of the circle
Thus.

Potential at the center of the semicircle